What is water's biggest advantage in extinguishing fire?

The biggest advantage of water in extinguishing fire lies in its ability to cool the fire. Water has a high specific heat capacity, meaning it can absorb a significant amount of heat before its temperature rises. When water is applied to a fire, it absorbs heat from the flames and the surrounding materials, effectively lowering the temperature below the ignition point and disrupting the combustion process. This cooling effect is crucial because it not only reduces the heat available to sustain the fire but also helps prevent re-ignition once the flames are extinguished.

While water can also aid in diluting flammable materials or displacing oxygen to some extent, its primary and most effective role in firefighting is cooling. Smothering flames or displacing oxygen are more relevant to other types of fire suppression approaches and aren't as significant in the context of water's unique properties. Thus, cooling remains the most critical advantage of using water in extinguishing fires.